The recruitment of the patients proceed with a two-step screening: 1) the Impact of Event Scale Revised (IES-R) will be administered to consecutive patients corresponding to the neurological inclusion and exclusion criteria, specifying in the instructions that they consider only the illness as the traumatic event. 2) Patients with scores above the cut off of 33 will be assessed with the SCID in order to confirm diagnosis of PTSD. The research protocol will be proposed to patients with PTSD who meet the inclusion/exclusion criteria, with an explanation of the aims of the study, its relevance for MS patients and the possibility that they may be included, by random assignment, in the treatment or control group for the period of the study, with the same timing and assessment tools. If they agree, they sign the informed consent. Patients will be randomised to the intervention (A) or control (B) group using a block-wise randomisation sequence (block size of 10). Assessment Measures: All patients are evaluated by neurologists with the Expanded Disability Status Scale (EDSS).